As a transition zone between aquatic and terrestrial systems, they usually have characteristics of both.
They provide vegetative cover to help moderate water temperature, provide food, nutrients and organic matter to the stream, stream bank stabilization, and buffer streams from excessive silt and surface run-off pollution. A wide variety of animals are attracted to these areas including insects, amphibians, reptiles, fish, birds, and mammals and many of these animals depend on these areas to exist. Suitable habitat (food, water, and shelter) is often provided in riparian areas to support these animals which may not occur in surrounding drier areas.
Streams and riparian areas are sensitive to urban development as removal of vegetation, paving near or over them, installation of culverts and pollution degrade the quality of these areas and impede there ability to function. For example, good quality streamside habitat is essential for ensuring healthy fish populations. Protecting riparian areas, while facilitating urban development that embraces high standards of environmental stewardship, is a priority for the government of B.C. Which is why the province developed the Riparian Areas Regulation (RAR). RAR provides the impetus for local governments to protect riparian areas during residential, commercial and industrial development in order to protect the heath, productivity and functioning condition of this important area.